The present invention relates to a cooling fan and, more particularly, to a high performance of cooling fan, which produces little noise during its operation.
In a computer or electronic apparatus, a cooling fan may be used with a heat sink to dissipate heat from the CPU. FIG. 1 shows a prior art cooling fan for this purpose. This structure of cooling fan comprises a housing, a winding assembly 81 mounted inside the housing, and a fan blade assembly 82 mounted inside the housing around the winding assembly 81. When electricity is connected to the winding assembly 81, a magnetic field is induced to rotate the fan blade assembly 82. The fan blade assembly comprises a center rod 83 coupled to a part inside the housing. Because the center rod 83 receives much heat during the operation of the cooling fan, the connection area between the center rod and the housing wear quickly with use, thereby causing the center rod to vibrate. When the center rod vibrates during the operation of the cooling fan, the rotation of the fan blade assembly becomes unstable, and much noise is produced.
The present invention has been accomplished to provide a container basket, which eliminates the aforesaid problem. According to one aspect of the present invention, the cooling fan comprises a circuit board fixedly mounted inside a housing around a shaft to hold a fixed winding assembly, a fan blade assembly coupled to the shaft of the housing, the fan blade assembly having a countersunk hole at the center of the hub thereof, an axle bearing secured to the shaft of the housing to support rotation of the fan blade assembly on the shaft, and a ring magnet fixedly mounted inside the fan blade assembly for enabling the fan blade assembly to be rotated on the shaft upon connection of electricity to the winding assembly. Because the hub of the fan blade assembly is supported on the axle bearing, the rotation of the fan blade assembly is stable. According to another aspect of the present invention, the fan blade assembly comprises two sets of blades radially extended from the hub and alternatively arranged at different elevations.